On another build I went with a stock aftermarket Radiator off Ebay and mounted it in the rear as you see here. About 95 % of the time, this worked well, but under some conditions, I would experience over heating. I later sold this Trike and the new owner corrected the problem by installing an air dam under the Trike to force air into the Radiator from under the Trike. My understanding is that they have not had a problem since.